arcstat.1

ARCSTAT(1) General Commands Manual ARCSTAT(1)

arcstat — report ZFS ARC and L2ARC statistics

arcstat [-havxp] [-f field[,field…]] [-o file] [-s string] [interval] [count]

arcstat prints various ZFS ARC and L2ARC statistics in vmstat-like fashion:

ARC target size
Demand hit percentage
Demand I/O hit percentage
Demand miss percentage
Demand data hit percentage
Demand data I/O hit percentage
Demand data miss percentage
Demand metadata hit percentage
Demand metadata I/O hit percentage
Demand metadata miss percentage
MFU list hits per second
Metadata hit percentage
Metadata I/O hit percentage
Metadata miss percentage
MRU list hits per second
Prefetch hits percentage
Prefetch I/O hits percentage
Prefetch miss percentage
Prefetch data hits percentage
Prefetch data I/O hits percentage
Prefetch data miss percentage
Prefetch metadata hits percentage
Prefetch metadata I/O hits percentage
Prefetch metadata miss percentage
Demand hits per second
Demand I/O hits per second
Demand misses per second
Demand data hits per second
Demand data I/O hits per second
Demand data misses per second
Demand metadata hits per second
Demand metadata I/O hits per second
Demand metadata misses per second
ARC hit percentage
ARC hits per second
ARC I/O hits percentage
ARC I/O hits per second
MFU ghost list hits per second
Metadata hits per second
Metadata I/O hits per second
ARC misses per second
Metadata misses per second
MRU ghost list hits per second
Prefetch hits per second
Prefetch I/O hits per second
Prefetch misses per second
Prefetch data hits per second
Prefetch data I/O hits per second
Prefetch data misses per second
Prefetch metadata hits per second
Prefetch metadata I/O hits per second
Prefetch metadata misses per second
Total ARC accesses per second
Current time
ARC size
Alias for size
Uncached list hits per second
Demand accesses per second
Demand data accesses per second
Demand metadata accesses per second
evict_skip per second
ARC miss percentage
Metadata accesses per second
Prefetch accesses per second
Prefetch data accesses per second
Prefetch metadata accesses per second
L2ARC access hit percentage
L2ARC hits per second
L2ARC misses per second
Total L2ARC accesses per second
L2ARC prefetch allocated size per second
L2ARC prefetch allocated size percentage
L2ARC MFU allocated size per second
L2ARC MFU allocated size percentage
L2ARC MRU allocated size per second
L2ARC MRU allocated size percentage
L2ARC data (buf content) allocated size per second
L2ARC data (buf content) allocated size percentage
L2ARC metadata (buf content) allocated size per second
L2ARC metadata (buf content) allocated size percentage
Size of the L2ARC
mutex_miss per second
Bytes read per second from the L2ARC
Bytes written per second to the L2ARC
L2ARC access miss percentage
Actual (compressed) size of the L2ARC
Compressed size
Compressed size percentage
Overhead size
Overhead size percentage
Bonus size
Bonus size percentage
Dnode size
Dnode size percentage
Dbuf size
Dbuf size percentage
Header size
Header size percentage
L2 header size
L2 header size percentage
ABD chunk waste size
ABD chunk waste size percentage
ARC data target
ARC data target percentage
ARC data size
ARC data size percentage
ARC metadata target
ARC metadata target percentage
ARC metadata size
ARC metadata size percentage
Anonymous size
Anonymous size percentage
Anonymous data size
Anonymous data size percentage
Anonymous metadata size
Anonymous metadata size percentage
Anonymous evictable data size
Anonymous evictable data size percentage
Anonymous evictable metadata size
Anonymous evictable metadata size percentage
MFU target
MFU target percentage
MFU data target
MFU data target percentage
MFU metadata target
MFU metadata target percentage
MFU size
MFU size percentage
MFU data size
MFU data size percentage
MFU metadata size
MFU metadata size percentage
MFU evictable data size
MFU evictable data size percentage
MFU evictable metadata size
MFU evictable metadata size percentage
MFU ghost size
MFU ghost data size
MFU ghost metadata size
MRU target
MRU target percentage
MRU data target
MRU data target percentage
MRU metadata target
MRU metadata target percentage
MRU size
MRU size percentage
MRU data size
MRU data size percentage
MRU metadata size
MRU metadata size percentage
MRU evictable data size
MRU evictable data size percentage
MRU evictable metadata size
MRU evictable metadata size percentage
MRU ghost size
MRU ghost data size
MRU ghost metadata size
Uncached size
Uncached size percentage
Uncached data size
Uncached data size percentage
Uncached metadata size
Uncached metadata size percentage
Uncached evictable data size
Uncached evictable data size percentage
Uncached evictable metadata size
Uncached evictable metadata size percentage
ARC grow disabled
ARC reclaim needed
The ARC's idea of how much free memory there is, which includes evictable memory in the page cache. Since the ARC tries to keep avail above zero, avail is usually more instructive to observe than free.
The ARC's idea of how much free memory is available to it, which is a bit less than free. May temporarily be negative, in which case the ARC will reduce the target size c.

Print all possible stats.
Display only specific fields. See DESCRIPTION for supported statistics.
Display help message.
Report statistics to a file instead of the standard output.
Disable auto-scaling of numerical fields (for raw, machine-parsable values).
Display data with a specified separator (default: 2 spaces).
Print extended stats (same as -f time,mfu,mru,mfug,mrug,eskip,mtxmis,dread,pread,read).
Show field headers and definitions

The following operands are supported:

interval
Specify the sampling interval in seconds.
count
Display only count reports.
December 23, 2022 Debian